AB0349 ANALYSIS EFFICACY OF ABATACEPT TREATMENT IN BIOLOGIC-NAÏVE AND BIOLOGIC-EXPERIENCED PATIENTS.
Authors: M. Borisova, G. Lukina, S. Yakov, E. Luchikhina, D. Karateev, A. Novikov, E. Aleksandrova, E. Aronova, S. Glukhova, E. Nasonov
Journal: Annals of the Rheumatic Diseases (2022)

Background Despite the high efficacy of rheumatoid arthritis (RA) therapy, in routine clinical practice, clinicians face questions about the choice of a second biologics, as well as the possibility of biologics monotherapy. Therefore, the specialties of biologics use in these categories of patients are of great clinical interest. This work is devoted to the study of the effectiveness of abatacept (ABA) therapy in biologic-naïve and biologic-experienced patients and in the subgroup of ABA monotherapy. Objectives To evaluate the effectiveness of ABA therapy between biologic-naïve and patients who had experienced an inadequate response to biological agents and in the subgroup of ABA monotherapy. Methods We prospectively enrolled and followed 91 patients with high RA activity (SDAI=28±13.4, CDAI=25±12) and an inadequate response of conventional synthetic DMARDs (mainly methotrexate, 70.3%) and biologics (mainly TNF-α blockers, 93%) were included in the study. Most of the patients were middle-aged (49±13.5), positive for RF (72.5%) and ACCP (77%) with moderate functional impairment - 1.4 (0.9-2). Patients were divided into two groups: biologic-naïve (48.4%, n=44) and biologic-experienced patients (51.6%, n=47). 18% (n=17) of patients had a history of an inadequate response of 2 or more biologics. The ABA monotherapy group (13%, n=12) was assessed separately. ABA were administered IV, 10 mg/kg according to the standard scheme. The evaluation of the effectiveness of the therapy was carried out according to the EULAR/ACR 2011 criteria using the intention-to-treat approach and SDAI, CDAI and the functional state using the HAQ. Results ABA led to a significant (p&lt;0.05) decrease in RA activity after 3 months of ABA therapy in all groups. After 6 months of treatment, there was a tendency towards an increase in the number of patients who achieved remission and low RA activity in the group of biologic-naïve patients, which continued to 12 months of therapy. So, after 6 months and 12 months in the group of biologic-naïve patients, the frequency of remission and low disease activity was 71% (n=25) and 76% (n=19) by SDAI, 75.6% (n=28) and 81.5% (n=24) by CDAI, respectively. Whereas, in the group of biologic-experienced patients - SDAI - 61.8% (n=21) and 69.2% (n=18), CDAI - 64.8% (n=22) and 77.8% (n=21), respectively. However, these differences didn’t reach significance. Similar results were obtained according to the EULAR criteria: after 12 months of treatment, the percentage of patients with a good response in both groups did not differ, 38% (n=14) in biologic-naïve and 38.4% (n=15) in biologic-experienced patients. ABA significantly improved functional status of patients, after 12 months the median HAQ of biologic-naïve and biologic-experienced patients were 0.7 (0.2–0.8) and 1.18 (0.7–1.6), respectively. More biologic-naïve patients achieved functional remission by HAQ after 6 and 12 months compared with biologic-experienced patients: 67% (n=23) vs. 33% (n=17), 62.5% (n=11) vs. 37.5% (n=9), respectively, but these differences didn’t reach significance. In the ABA monotherapy group after 6 months treatment, a good response by EULAR criteria was achieved in 10% (n=1) patients, while in the group of ABA+csDMARDs therapy in 43.5%, p=0.04. After 12 months the trend towards a more pronounced response in the combination therapy group persisted (11%, n=1 and 42%, n=28, respectively), but no significant differences were obtained. Conclusion Abatacept has shown significant improvement clinical and functional status in all studied groups. There were no significant differences in response to ABA therapy between biologic-naïve and biologic-experienced patients. ABA monotherapy were significantly worse compared with the combination therapy of ABA and csDMARDs after 6 months. After 12th month observation, this tendency continued, but no significant differences were achieved. This is probably due to the small number of patients on ABA monotherapy and, as a result, to the insufficient statistical representativeness of the sample. Disclosure of Interests None declared